Monday, July 22, 2019

First Chapter of Lord of the Flies Essay Example for Free

First Chapter of Lord of the Flies Essay The first chapter of Lord Of the Flies introduces Ralph at the very start roaming the jungle. This contributes to the mysteriousness of the literature. Not telling you where he came from or why he is there makes the story enticing and entertaining. The author was adding to the rising action. The setting in the very beginning was the Jungle. After Ralph walks for a small amount of time, a voice calls out to him asking for help, and to wait up. This is another way to make the story seem mysterious. He learns it is a boy with the nickname Piggy. Piggy joins Ralph and they walk to a lagoon. There they find a conch shell and Ralph blows through the conch which then calls on an large amount of boys. The author most likely added this to make another curve to the story. To show how much about the place Ralph and Piggy didn’t know. When the large group arrived, a boy named Jack Merridew asked where the ship was, and where an adult was. This showed how ignorant Ralph was because he had no clue what the conch sound meant to the people that were already there. Then Johnny and the twins Sam and Eric arrived along with many other younger and older boys. They talk as if they all have an education which shows they were also put here, not born here. The dialog seems modern and easily understandable, which shows that the setting is more recent than historical. Ralph is voted leader and commands that they explore to see if where they are is an island. Accompanying Ralph is Simon and Jack. Piggy is left behind to log names, which upsets him. The reason the author wrote about the exploration is to show the others don’t know where they are either. Throughout the venture, the boys are faced with a series of things in their path. They push a boulder off a cliff. The author most likely added this to show they weren’t hopelessly stranded on the island. The end of the chapter the boys realized they were hungry. They searched for food and found a pig, in the grips of the ‘creepers’. The author didn’t explain what the creepers were and it made it much more elusive. Jack fails to stab the pig quick enough and he made up excuses as to why he couldn’t. It shows that he isn’t nearly as tough as he lead on to be. He slams his knife into the tree to show he is in fact still the alpha male. The first chapter left many unanswered questions.

Religion Essay Example for Free

Religion Essay 1.) As a person of goodwill, explain the necessity of establishing rapport, amity, and concordance among the various religions in Asia and the world; and more specifically among Muslims and Christians in the Philippines. Why is religion a positive contributor towards peacemaking but at the same time can be a source of societal turmoil? In what way can Asian religions transcend divisiveness by standing side by side with other religions, without losing their very own unique creeds or belief-systems? Based on the films about Muslim Filipinos shown in class, please explain in what way Christians and Muslims can utilize their respective religions for peace and harmony in Mindanao? Answer these questions by citing concrete cases to prove your point (30 points). It is necessary to establish rapport, amity, and concordance among the various religions in Asia and the world more specifically among Muslims and Christians in the Philippines in order to better understand their systematic beliefs, values, and behavior, acquired by people as a member of their society. These patterns are systematic because their manifestations are regular in occurrence and expression: they are shared by member of a group. It is also necessary to build friendship and connection among diverse religions in Asia and the world to build a better society and to have peace in every nation. In such a society it is very important to have harmony and respect amongst the different religions. We must distinguish between belief and respect. Belief refers to total faith, which you must have in your own religion. At the same time you should have respect for all other religions. This tradition of believing in ones own religion and having respect for others. In every religion, there are transcendent things that are beyond the grasp of our mind and speech. For example, the concept of God in Christianity and Islam and that of wisdom truth body in Buddhism are metaphysical, which is not possible for an ordinary person like us to realize. This is a common difficulty faced by every religion. It is taught in every  ­religion, including Christianity, Buddhism, Hinduism and Islam, that the ultimate truth is driven by faith. As far as the Muslims are concerned it is appropriate for them to have complete devotion to Allah while praying in the mosques. This is also the same with Buddhists who are completely devoted to the Buddha when they pray in Buddhist temples. A society, which has many religions should also have many prophets and sources of refuge. I want to emphasize that it is extremely essential to sincerely believe in their respective religions. Usually, it is very important to distinguish between belief in one religion and belief in many religions. Religion is a positive contributor towards peacemaking but at the same time can be a source of societal turmoil because religion is a perennial and perhaps inevitable factor in both conflict and conflict resolution. Religion, after all, is a powerful constituent of cultural norms and values, and because it addresses the most profound existential issues of human life (e.g., freedom and inevitability, fear and faith, security and insecurity, right and wrong, sacred and profane), religion is deeply implicated in individual and social conceptions of peace. To transform the conflicts besetting the world today, we need to uncover the conceptions of peace within our diverse religious and cultural traditions, while seeking the common ground among them. Traditionally many people focus on how wars and conflicts are seemingly undertaken for religious reasons, or at least undertaken in the name of religion. A significant problem with organized religion and belief, as this relates to peace and conflict, is individuals and groups often confuse the map (their socially-learned version of reality or culture or religion) with the territory (or ultimate reality). Thus people believe that their personal or subjective version of reality or religion is valid, while other views are invalid. Instead it can be argued that the many maps are different, but possibly equally valid interpretations and attempts to understand the same underlying reality or territory. Asian religions can transcend divisiveness by standing side by side with other religions, without losing their very own unique creeds or belief-systems through banding together in interfaith dialogue, cooperation, and religious peacebuilding. The first major dialogue was the Parliament of the Worlds Religions at the 1893 Chicago Worlds Fair, which remains notable even today both in affirming universal values and recognition of the diversity of practices among different cultures. The 20th century has been especially fruitful in use of interfaith dialogue as a means of solving ethnic, political, or even religious conflict, with Christian–Jewish reconciliation representing a complete reverse in the attitudes of many Christian communities towards Jews. Christians and Muslims can utilize their respective religions for peace and harmony through sharing the main morals and conducts that are for the benefit of humanity and nature. They believe in the same basic morals that are important for people to follow in order to live in peace, harmony, and love in communities with different faiths and cultures. And to through tolerance, respect and cooperation with respect in each other’s religions. 2.) Explain why Islam is considered the â€Å"most misunderstood religion†. What are some historical, sociological and cultural reasons that paved the way for a misunderstanding of the true nature of Islam among non-Muslims and even among Muslims? Islam means â€Å"submission to the will of God in all areas of one’s life†. Muslim means, â€Å"One who submits to God’s will†. These Arabic words are actually non-sectarian terms if we look at the context of these words in the Qur’an. Can we use the term â€Å"Muslim† in its universal implication to include all believers in One God? Can we use the term â€Å"Muslim† to any person (irrespective of religions) who strives sincerely to submit to the will of God in his life? [Hint: Consider the Islamic doctrine of Risalah (Progressive Revelation) and the Islamic view of the universality of God’s calling of prophethood] (30 points). Islam is considered the â€Å"most misunderstood religion† because most of the time it is considered as a violent religion and is likely â€Å"to encourage violence among believers†. And there is also some outright falsehood for example, â€Å"God sent prophets to every nation for their guidance.† But, According to the â€Å"Doctrine of Progressive Revelation†, Islam is very universal since it admits that Allah sent prophets to everyone whereas Jews believe that prophets only come from them because they are the â€Å"chosen people of God.† Another example, â€Å"One of the missions of the Prophet of Islam was to bring peace and unity to the feuding tribes, the Jahiliah or the ignorant Arabs of the pre-Islamic days. This he succeeded in doing as narrated in several verses of the Qur-an†. The message of Allah were brought by one Prophet and recorded in one holy Qur-an. There is no other Qur-an, or versions or it, or editions which carry different texts. The hold Qur-an is not in the form of Gospels by Muslim saints or ulama. The holy Qur-an is just the record of the messages of Allah in the Arabic of the period. Translations of the Qur-an may be different in minor ways, but they are not accepted as the holy Qur-an. Only that in the original Arabic is accepted. So there can be no differing text or Gospels or versions which can result in differences in the messages or teachings of Islam. Yet, clearly there are differences, serious differences, so serious that Muslims are divided sometimes into warring sects. One of the reasons that paved the way of misunderstanding the true nature of Islam among non-Muslims and even Muslims are the â€Å"media†. Media is the greatest factor on how people view their surroundings. Somehow, criticizing the Islam brings them more readers/viewers. We tend to judge and generalize things without knowing the exact story behind those issues. Infact, the worl Islam means peace, purity, submission and obedience. In the religious sense, Islam means submission to the will of God and obedience to His law. Yes, we can use the term â€Å"Muslim† in its universal implication to include all believers in One God, as well as, to any person (irrespective of religions) who strives sincerely to submit to the will of God in his life because â€Å"Muslim† believe that God is eternal, transcendent, absolutely one (the doctrine of tawhid, or strict or simple monotheism), and incomparable; that he is self-sustaining, who begets not nor was begotten. 3.) Write a â€Å"reflective synthesizing essay† that answers the following questions: In the future prospect, will the Asian religions move from rhetoric unity and act as one to solve the common problems affecting humanity? As for Asian countries, will they achieve political independence from the clutches of Western neo-colonialism? Is there a need to abandon our cherished worldview and values in the name of development? How will the Asians reconcile their adherence to Asian ethos and at the same time open to the demands of globalization? How will the differing Asian worldviews and religions be properly harnessed to promote nationalism among Asians and global cooperation among countries in the world? (30 points) Yes. In the future, the Asian religions will move from rhetoric unity and act as one to solve the common problems affecting humanity to have a better nation, to have a respect on one another, to fix the unjust and destructive situations. There is no need to abandon our cherished worldview and values in the name of development but rather preserve it and continue following those values to build a progressive and advance nation. With their differing Asian worldviews and religions they can create different ideas and new innovations but with respect with one another’s point of view, and to accept what other countries have made, to promote nationalism among Asians and global cooperation among countries in the world. 4.) Explain what made Japanese civilization unique in its approach to establishing a pro-active Asian civilization capable of having positive ethical patterns as fountainhead of their development? Explain why it is not just enough to simply support one’s parents for one to be called â€Å"filial†; what are therefore the other requirements to be able to truly say that one has completely conducted oneself as â€Å"filial son/daughter† to one’s parents? What makes Indian civilization stuck into conservatism? What are some of the positive role that the caste-system plays in Indian civilization? What are also the negative aspects of the caste system to Indian civilization? Explain in what way did Japan show a purposive and planned-out blueprint for development in their history? (30 points) It is not just enough to simply support one’s parents for one to be called â€Å"filial† because we owe our parents a lot- because of them we able to eat three meals a day, sometimes even more. They give us clothes and sometimes the things that are beyond our needs. They send us to school. But more than simply supporting us in the most basic sense of supporting, our parents loves us. It now becomes something different because when we love them back, we do not do so out of indebtedness. We give our love freely, and not as a payment with a certain interest. Most of all, because of this special filial relationship with them that we had since birth, we also respect and obey them. We not only support our parents, but serve them. The Indian â€Å"caste system† made it stuck into conservatism. The positive roles that the caste-system plays in Indian civilization, provides a sense of community and belongingness. And the two main strands of thought: Divine will- the belief that a hierarchical social structure is part of the divine intention for natural order, and the Purity- the need to emphasize the importance of ritual purity and impurity. But there is also a negative aspect of caste-system to Indian civilization. For example, marrying someone from a different caste, whilst not officially outlawed, is generally discouraged. They only lived, ate, and worked within their group. This was based on the idea that people are different and should have different roles. And a person born into one caste never changed castes and very seldom mixed with members of other castes. Castes were unchanging groups but people from the lowest caste were told that they have to serve the other castes so that they can be reborn into a higher caste in their next life.

Sunday, July 21, 2019

Power Blackout Preventing By Power Swing Detection

Power Blackout Preventing By Power Swing Detection Power Blackout Preventing By Power Swing Detection  and Out-Of-Step Protection   Power system disturbance, such as fault occurrence, automatic reclosing, and large loads disconnection. These conditions force the generating units to adapt with the new load condition but the generators cant do this instantaneous due to the inertia. This cause a power swing. It may be stable power swing or un stable power swing. In the stable power swing the generator can return to the new equilibrium state. On the other hand, in the un stable power swing the generator cant reach to the steady state operation and run out of step and may lead to the blackout. in the case of power swing the load impedance may enter into the operation characteristic of the distance relay and case unwanted tripping for the transmission lines. So, the distance relay isnt supposed to tripe under the power swing if stable or unstable to give the system the availability to return to its steady state. A power swing block PSB its a function inside the modern distance relays that prevent unwanted tripping by block the tripping signal in case of stable or unstable power swing. However, when the fault happens due to a Power swing it must be cleared very rapidly with high level of dependability and selectivity. Out-of-step trip (OST) in is a function that included in the modern relays to achieve the separation of the power system under the unstable power swing. The major aim of this function to differentiate between the stable and unstable power swing and separate the power system into predetermined zones to achieve the stability and continuity of the service. Key words:  Power Swing Detection; Out of Step Protection; Distance Protection. USA United states of America NERC North American Electric Reliability Corporation N-1criterion Most security rules therefore call for the system to be able to withstand the loss of any single component UCTE Union for the Coordination of the Transmission of Electricity PSB Power Swing Block OOS Out-of- Step OST Out-of-Step Trip TOSB Setting Time of out-of-step Blocking TOST Setting Time of out-of-step Tripping Figure 1 Causes due to different disturbances Figure 2 Two-Machine System model Figure 3 The Power Angle Curve Figure 4 The Equal-Area Criterion (Figure shows a fast fault clearance and a stable swing) Figure 5 Unstable System due to Slow Clearing Time Figure 6 Wrong operation of distance relay due to Power Swing Figure 7 Two-Blinder Power Swing Detection Scheme Figure 8 Automatically sized power swing area. Figure 9 Monotony criterion. Figure 10 Continuity criterion Figure 11 Smoothness criterion. Figure 12 Logic for power swing detection Figure 13 Impedance trajectory for 3-machine power swing Figure 14 Impedance trajectory during stable power swing. Figure 15 Internal fault B-G during a power swing. Figure 16 Internal fault B-G with single pole trip during a power swing. Figure 17 External fault in BC-G during a power swing. Figure 18 Example of a reverse busbar fault during power swing. Figure 19 Rotor angle and impedance trajectories for stable power swing. Figure 20 Rotor angle and impedance trajectories for unstable power swing. Figure 21 Basic signals for out of step detection. Figure 22 Logic for special out of step tripping. In the previous few years we have suffered from big disturbances in the power system which caused complete blackout and millions of users including the industry have suffered from big economical losses. These disturbances cause big fluctuations in active and reactive power, low voltage, voltage instability and angular instability between the generated power and consumed power which results in loss of generation and load which effected on both sides the power generation and the end customers. During the steady state operating condition, the power systems operates on the nominal frequency (50Hz or 60Hz) +/- 0.02 Hz and Voltage=Nominal voltage +/- 5% [1]. The complete synchronism of nominal frequency and voltage at the sending and receiving ends make complete balance of active and reactive power between generated and consumed active and reactive powers. Power system faults, line switching, generator disconnection, and the loss of large blocks of load result in sudden changes to electrical power, which is due to the causes shown in Fig 1. Disturbances Line Switching Generator Disconnecting Paralleling other Generator Addition of load Loss of load Causes Loss of Synchronism Between Voltages Loss of Synchronism Between phase sequence Loss of Synchronism Between phase angles Loss of Synchronism Between frequencies 1.1. Blackout History 1.1.1 Some blackouts became in 2003 (during six weeks). in the northeastern USA and central Canada and in Europe, which affected more than 100 million people. On 14 August the northeastern USA and central Canada: †¢ 62 GW power outage, affected 50 million people. †¢ power supply restoring took some days. On 14 August London †¢ 724 MW power outage, affected 410 thousand people. †¢ power supply restoring took 40 minutes. On 2 September the southern Malaysia †¢ affected 5 states (out of 13) in Malaysia, including the capital Kuala Lumpur. †¢ power supply restoring took 5 hours. On 5 September Birmingham †¢ 250 MW power outage, affected 220 thousand people. †¢ power supply restoring took 11 minutes. On 19 September nine US states and parts of Ontario, Canada †¢ affected 4.3 million people. †¢ cause hurricane Isabel. On 23 September Denmark and Sweden †¢ affected 5 million people. †¢ power supply restoring took 4 hours. On 28 September Italy †¢ affected 57 million people. †¢ power supply restoring took 4 hours. [1], [2], [3] Blackout in the Northeastern USA and Central Canada 14 August 2003 Initially the event was the tripping of the power line that caused by the short circuit to ground due to tree contacts. Blackout in the northeastern USA and central Canada was studied by The North American Electric Reliability Corporation (NERC) and some contravention of safety and reliability standards was identified: †¢ following the outage of the first 345-kV line, dispatcher of the power system did not make the necessary actions to return the system to a safe operating state within 30 minutes to fulfillment of N-1criterion which mean Most security rules therefore call for the system to be able to withstand the loss of any single component. When a power system satisfies this criterion, it is said to be N-1 secure †¢ dispatchers of neighboring transmission system were not informed about this situation. †¢ insufficient training of dispatchers. †¢ functionless monitor system in part of the power system. Reliable and safety operation of the power system The North American Electric Reliability Council (NERC) have developed the operating of the system and planning standards to confirm the reliability and the stability of a transmission network that are depend on seven key concepts: Balance power generation and demand continuously. Balance the reactive power supply and the demand to keep scheduled voltages. Monitor the power flow over the transmission lines and other facilities to ensure that thermal (heating) limits are not exceeded. Keep the system in a stable condition. Operate the system so that it remains in a reliable condition even if a contingency occurs, such as the loss of a key generator or transmission facility (the N-1criterion). Plan, design, and maintain the system to operate reliably. Prepare for emergencies Blackout in Italy on September 28, 2003 The situation in the Italian power system before blackout wasnt exception. †¢ total load of Italy was 27 444 MW. †¢ 3 487 MW pump load. †¢ 6 951 MW physical import to the Italian power system. †¢ some transmission lines in neighboring power systems were out of service by reason of scheduled maintenance. †¢ the Italian power system was connected to neighboring power systems via 15 transmission lines. Sequence of events of the blackout in Italy The initial event was the 380 kV line tripping in Switzerland. Fewer than 25 minutes after this event the Italian power system ceased to operate synchronized to the UCTE system. Union for the Coordination of the Transmission of Electricity 03:01:42 the 380-kV line tripping in Switzerland (Lavorno Metlen) line was heavy loaded at 86%. †¢ The cause of tripping a wire contacted to a tree. †¢ The attempts of single-phase auto-reclosing and also the attempt of the operators to put this line back into operation were not successful and the line was disconnected by its protection device, due to high phase angle (42 °). †¢ After the Lavorno Metlen line tripping, the other 380 kV line in Switzerland (Sils Soaza) became overloaded. 03:11 the Swiss dispatch asked the Italian dispatch to reduce the import of Italy by 300 MW (on scheduled value). 03:25:21 the second overloaded 380 kV line tripping in Switzerland (Sils Soaza). 03:25:25 the third overloaded 380 kV line tripping in Switzerland. 03:25:26 the interconnection line Austria Italy (Lienz Soverenze) tripping. 03:25:33 the Italian power system started to disconnect from the UCTE system After disconnection Italy from the UCTE system the frequency in the Italian power system dropped suddenly, caused by the negative imbalance between power injection to the system and system load. The blackout in the Italian power system became within fewer than 3 minutes. 21:40 official announcement about emergency cancellation in whole power system of Italy. Main causes of the blackout in Italy The initial event was the 380-kV line tripping in Switzerland in consequence of the wire the tree contact. The attempts of single-phase auto-reclosing and also attempt of the operators to put this line back into operation were not successful and the line was disconnected by its protection device, because phase angle was too high. We can see two causes: †¢ insufficient protective zone under the transmission lines. †¢ overloaded lines. After the first 380 kV line tripping in the Swiss power system other power lines became overloaded. That means that the safety N-1criterion was non fulfillment in the Swiss power system. We can see other causes: †¢ Violation of basic safety N-1criterion. †¢ high import to Italy. †¢ incomplete information about neighboring power system. †¢ pump load was stopped too late, by automatics. 1.1.2. System disturbance in the UCTE system on 4 November , 2006 The system disturbance in the UCTE system on 4 November, 2006 was the most serious incident in the UCTE system within an interconnected Europe history. The system disturbance started in the German transmission system on 4 November 2006, around 10 p.m. This disturbance split the UCTE system into three separate parts (West, North-East and South-East). More than 15 million households were affected by an interruption of the electricity. The UCTE system resynchronization was completed 38 minutes after the splitting. [4] What happened? On 18 Sept. 2006, the shipyard (Meyerwerft) sent a request to E.ON Netz to disconnect two 380 kV line Conneforde-Diele for the transport of the ship through the Ems River to the North Sea on 5 November at 01:00. As a switching in the last several times. The E.ON Netz operator did a power flow calculation and verified fulfillment of safety N-1criterion using numerical computation. Analysis did not show any problem and so the operator provisionally approved the request of the shipyard and informed neighbouring transmission system operators (RWE Germany and TenneT Niederland). On 3 November (around 12.00) came a new request to E.ON Netz for a time change of two power lines Conneforde- Diele switching on 4 November at 22:00. A provisional agreement was given by E.ON Netz after a new analysis. But RWE and TenneT operators were not informed about this change at the same time. Only at 19:00 on 4 November E.ON Netz informed TenneT and RWE TSO about the new time for switching off the Diele -Coneforde line. At 21:29 according to the load flow calculation made by E.ON Netz did not indicate any violation of limit values. But N-1criterion was checked without numerical computation, was checked based on an empirical evaluation of the grid situation only. Sequence of events †¢ At 21:38 a 21:39. power lines Conneforde-Diele were disconnected. †¢ At 21:39. after the switching operation, two 380 kV lines was overloaded. †¢ At 21:41. RWE dispatcher informed E.ON Netz about the safety limit value on the line Landesbergen-Wehrendorf (an interconnection line between E.ON Netz and RWE TSO). Later investigation uncovered different protections setting on this line. †¢ Between 22:05 and 22:07, the load on the 380 kV line Landesbergen-Wehrendorf increased and the RWE operator called E.ON Netz at 22:08 with the request for urgent intervention due to return to the stable grid condition. †¢ E.ON Netz made an empirical assessment of corrective switching measures without making load flow estimation for checking the N-1criterion. E.ON Netz expected that coupling of the bus-bars in the substation of Landesbergen would reduce of load on the 380 kV line Landesbergen- Wehrendorf. But this line was overload more than 100% and so was tripped and the other lines became overloaded. †¢ At 22:10:28 the UCTE system splitted to three areas after the power lines switching in E.ON Netz, RWE, the Austrian power system and after disconnection of interconnection lines: Croatia Hungary and Marocco -Spain. The initial event of the system disturbance in the UCTE system was scheduled switching off two power lines. Main causes The investigation identified two main causes of the disturbance as well as some critical factors which had significant influence on its course: non fulfillment of the N-1criterion or verified its fulfillment without numerical computation. †¢ insufficient co-ordination between the transmission system operators. †¢ dissatisfied power plant operation in emergency: tripping of generation units (particularly wind power plants) during disturbance and uncontrolled reconnection of generation units. †¢ limited range of action available to dispatchers. †¢ insufficient training of dispatchers. 1.2. Blackout Causes and Risks A blackout is a power outage. This state means the loss of the electricity supply for a part of the power system or the whole power system. A. Blackout Causes Natural causes Lightening. Rain. Snow. wind storm. Technical Failures Transformer faults. Short circuits. Human error Error of judgment. Insufficient co-ordination between the transmission system operators. Insufficient training of dispatchers. Terrorism Bombing. cyber-attacks. B. Blackout Risks power system equipment damage. heavy economical losses. jeopardy of economy functioning. life paralysis in stricken parts of country. Several blackouts cases became in the world of last years. Causes of these disturbances were various technical, bad weather conditions, human failing. C. Some impacts of Northeastern Blackout Ford Motor Company The stoppage of factorys furnace cause to convert the molten metal to solid metal. The company reported that it need a week to clean the furnace. Marathon Oil Corporations The blackout was responsible for making suddenly shutdown procedures at Marathon refinery. in those procedures, a carbon monoxide boiler failed to shut down correctly, causing a small explosion. As a precautionary measure, the police vacate one-mile sector around the complex. Daimler Chrysler Daimler Chrysler lost production at 14 of its 31 factories. 6 of those were assembly factories with paint shops. The company reported that, in total, 10,000 vehicles were moving through the paint shops during the blackout had to be scrapped. New York City New York Citys mayor estimated that the city would pay almost USD 10 m in overtime related to the outage. Airports Airports were closed in Toronto, Newark, New York, Montreal, Islip, Cleveland, Erie and Hamilton. Together they cancelled over 1,000 flights 2.1. Introduction Under steady state conditions the power generation and the load are balanced and the power systems operate in nominal frequency 50 Hz or 60Hz with some deviations 0.02Hz for the large system and 0.05 for the small system. Taking into consideration the two-machines shown in Fig. 2, the power transmitting can be denoted by the following equation: Where: ES is the voltage of machine S ER is the voltage of machine R ÃŽÂ ´ is the angle by which ES leads ER = QS-QR QS is the rotor angle of machine S QR is the rotor angle of machine R ZT is the total impedance between the two machines consisting of ZS, ZR, and ZL ZS + ZL + ZR ZS is the impedance of source S ZR is the impedance of source R ZL is the impedance of the transmission line The Power angle curve in Figure 3 clears the relation between the power transmit and the angle ÃŽÂ ´ (the angle between the two ends). The relation clear that the power transmit increase with nonlinear direct proportion with the angle ÃŽÂ ´ when ÃŽÂ ´ lie between 0 ° : 90 ° . After ÃŽÂ ´ equal 90 ° the power decrease with nonlinear inverse proportion with the angle ÃŽÂ ´. The power system are worked well at the point of maximum power at ÃŽÂ ´ = 90 ° so The maximum power is presented as the following equation: Power Swing definition It is a changing in the Electrical power due to the changing of the rotor angle (ÃŽÂ ´) either Increasing or decreasing response to : line switching, Load disturbances , loss of generation, short circuit faults and other power system disturbances. During the large disturbance in the power system the transmit electric output power suddenly decreased from P0 to Pf as shown in Fig.4 but the mechanical torque (that connected to the generator and equivalent to the output electrical power P0 at the moment before reducing the electrical power) cant reduce suddenly to equivalent Pf so this unbalance cases accelerating in the rotor of the machine and increasing in the angle (ÃŽÂ ´). The assume of this analysis is neglects the operation of the voltage regulator that control on the excitation and change the machine voltage, and the governors that change the mechanical input power If the fault is cleared at the point of ÃŽÂ ´c the output electric power will increase and become greater than the input mechanical power so the machine will start to decelerate but because of the inertia the machine rotor cant decrease suddenly and reached to ÃŽÂ ´e. Assume area 1 refer to the accelerating energy, and area 2 refer to decelerating energy, so when the fault cleared quickly the two areas can be equal before the angle reach to the limiting angle ÃŽÂ ´L and the system will return after some oscillation to the last operating point at ÃŽÂ ´0 and that call Stable power swing. On the other side if the fault didnt clear quickly and spend more time, the angle ÃŽÂ ´ will move far away enough to make the two areas (accelerating area de accelerating area) not equal before the angle reaches to ÃŽÂ ´L as shown in Fig. 5 and due to the inertia the the angle will reach to the limiting angle and after this point the electrical output power will decrease again to be less than the mechanical input power so the machine rotor will accelerate and the rotor angle will increase above 180 and the pole slipping will happen . this case called out of step condition or unstable power swing condition Power Swing Effect on the Distance Relay Under Steady State Operation the impedance of the load not enter into the operation characteristic of the distance relay but in the case of power swing the load impedance may enter into the operation characteristic of the distance relay and case unwanted tripping for the transmission lines, and may be cause cascading tripping and stoppage of major sections of the power system. The distance relay isnt supposed to tripe under the power swing if stable or unstable to give the system the availability to return to its steady state. A power swing block PSB its a function inside the modern distance relays that prevent unwanted tripping by block the tripping signal in case of stable or unstable power swing thus, The Power Swing Block function is used to differentiate between the power swing and the fault. However, when the fault happens due to a Power swing it must be cleared very rapidly with high level of dependability and selectivity. The zones must be separated hoping to avoid causing large deference of the rotor angle between groups of the generators and loss the synchronism between them, equipment damage and the blackouts. Perfectly, the power system should be separated into predetermined zones to achieve a balance of load-generation in each of the separated zones. In some cases, load shedding is essential to avoid a whole blackout of the area where the load of the separated area is more than the local generation Controlled tripping of the power system relays in the case of an Out-of-Step condition is very essential to prevent extensive outages, equipment damage and shutdown of large areas in the power system. Out-of-step trip (OST) in is a function that included in the modern relays to achieve the separation of the power system under the unstable power swing. The major aim of this function to differentiate between the stable and unstable power swing and separate the power system into predetermined zones to achieve the stability and continuity of the service. Power Swing Detection Methods. Following is a brief discussion of the methods that have been used for detecting power swings and schemes used for OSB and OST functions. Traditional method based on rate-of change of impedance and the recently method is Power-Swing-Detection Algorithm Based on Continuous Impedance Calculation. 2.2.1 Traditional Rate of change of Impedance Schemes for Detecting Power Swings. In the conventional method, the relay measure and calculate the positive sequence impedance and the change rate of the impedance. During the steady sat operation the measured impedance depends on the load impedance and the distance between the protection zone of the distance relay and the point of measurement. The impedance move in trajectory depends on the operation case. In the case of the fault if the impedance moved rapidly to the fault zone. On the other case during the power swing the impedance moved slowly at some trajectory with a rate depend on the slip frequency between the generators. Thus, the variation of the impedance movement speed used to distinguish between the power swing and the faults. The concept of this method that using of two measuring impedance and separated them by ΆZ and used a calculated timer. When the measured impedance moved through the first one the timer will start running. If the measured impedance cross the second impedance before the time r expire, that indicated to a fault case. If the timer expired and the impedance didnt reach to the second impedance that indicated to a power swing case. Two-Blinder Scheme for PSB and OST Functions The two blinder scheme of the rate-of-change of impedance method is used in many relays, separated by ΆZ, and a calculated timer TOSB. The two-blinder scheme is shown in Fig. 7. This figure shows Two parallel blinders are on the right side of the X-line impedance and another two parallel blinders are on the left side. The timer TOSB is start running when the impedance move through the outer blinder During the fault condition the impedance moved rapidly through the outer blinder to the fault zone and cross the inner blinder before the TOSB expire. On the other case during the power swing the impedance moved slowly through the outer blinder and stay between the two blinders even TOSB will expire. This scheme can be used for a power swing blocking function to block the distance relay to prevent unwanted tripping. During Power Swing Blocking declared a reset timer should be used in order to force the relay to delay the assert when TOSB expired. The Out-Of-Step tripping (OST) can use the previous scheme expect that the calculated timer for out of step (TOST) is shorter than TOSB. In the case of power swing the impedance locus cross the outer blinder and at this point the timer will start running. If the timer TOST expires before the impedance locus cross the inner blinder, the power swing condition will declare, and if the impedance locus cross the inner blinder before timer TOST expires, the out of step condition will declare. The Out-Of-Step tripping function can be set to tripe instantly or wait for a time. The Instantly tripping referred to as predictive tripping or early tripping. The other case is referred to as delayed tripping. In some applications, the tripping is required only when the out of step condition occurs a determined number of times. It is essential for some application to use both OSB and OST functions, and it available to use them in the Same relays using the two blinder scheme technique. According to difference in speed of impedance trajectory in the case of stable power swing and unstable power swing, two timers are required TOSB and TOST whereas TOST is shorter than TOSB to be fit with the rapidly speed of the impedance trajectory in case of unstable power swing 2.2.2. Power Swing Detection Algorithm Based on Continuous Impedance Calculation The traditional methods of power swing detection are depend on a complex study for the power system to reach to the correct settings, but the setting are fixed and not adapt to any change in the system condition because of it is not possible to study the system under unstable power swing. therefore, the power system study doesnt deem the worst cases and the bad conditions, so in the case of power swing or out of step condition it may lead to unwanted tripping. The following method described below solves these problems. It is based on a continuous impedance calculation [5]. This method has the following features: It is not required for settings or complex calculation detect the power swing with frequencies range from 0.1: 10 Hz. Detect the power swing in the case of single-pole open condition or fault condition. Unblocking of distance protection relay if there both faults and power swing. Out-of-step tripping during unstable power swing. The Continuous Impedance Calculation method depend on taking four sample of the impedance per one cycle of the power system frequency the three phase each phase separately. During the power swing the impedance trajectory moved on an oval path, and when it enters the power swing area, as shown in Figure 8, the algorithm of power swing start its analysis for each phase and calculate the power swing area automatically. In the case of power swing, the power swing detection will detect it, and stay active even if the trajectory of the impedance leave the power swing zone. The algorithm computes the new values of R X, and compares them with the previous values that placed in the memory. The main criterias of the power swing detection methods are monotony, continuity and smoothness. The thresholds are calculated dynamically. This automatic adaptability to the trajectory speed change, enables the algorithm to detect the low frequency and the high frequency power swing. Monotony: The algorithm will check the direction of the derivat

Saturday, July 20, 2019

One is Happy When He Believes That He is Happy :: Happiness Essays

Not many people are happy, but all the libraries are filled with books on happiness, and this very fact should make us curious. The Ancients gave us dozens of recipes on how to conduct a happy life, each of them contradicting the other, or at least, with very dissimilar opinions. The Modernity has its own solutions up to the negation of the very possibility of having a happy life. And recently, mister Francis H. came up with his own idea of happiness. He argues that the problem of happiness can be reduced to wealth, knowledge and a personal belief of being "in control" of one's own life. Let's at first consider these factors. Wealth is important, according to mister Francis H., because it allows the satisfaction of one's basic needs. It seems to me that if it was true, the Ancients had no chance to be happy at all and we can not be happy as well, since in the time to come people will be even more wealthy than they are now (see later on the part of my essay "On Future") and able to better satisfy their needs. Well, I guess the notion of wealth is just relative. Same as basic needs which can cause even more trouble. What are basic needs? Color TV and refrigerator or your own jet plane? Or maybe just a barrel in a harbor as Diogenes showed us? Knowledge. In my opinion the problem with knowledge may be similar to the wealth issue. Knowledge in general (meant as scientific knowledge) has increased dramatically over the last centuries, but arguing that this has contributed to general happiness is at least risky, not to mention superfluous. This problem has two main aspects, firstly, its relativity (as in the case of wealth); we can fly to Venus and kill most of the microbes but there is still much more to be done. Secondly, its validity in the pure aspect, as giving us answers about the world and life in general. On the other hand, as far as personal knowledge, or education, or one's intelligence goes, I don't really see any direct correlation between what one knows and is capable of doing to his own happiness. History can supply us with arguments to both sides. If you don't like history, go to the nearest psychiatric hospital to see the lack of correlation. Here we come to the third aspect of happiness: The personal belief of being "in control".

Friday, July 19, 2019

Free Waste Land Essays: Underlying Myths in The Waste Land :: T.S. Eliot Waste Land Essays

Underlying Myths in The Waste Land The underlying myths that Eliot uses to provide a framework for "The Waste Land" are those of the Fisher King and the Grail Quest. Both of these myths come to Christian civilization through the ancient Gaelic tradition. Neither is found in the Bible, but both were important enough to Europeans that there was a need to incorporate them into the new European mythology, and so the stories became centered on the story of the death and resurrection of Jesus. Other examples of these myths can be found in Eschenbach's Parsifal, in de Troyes' Quest of the Grail, and in the various stories of the grail quest surrounding King Arthur and his knights. It is described in works of anthropology, as well, two of which Eliot recommends to readers: Jessie L. Weston's From Ritual to Romance and Sir James Frazier's Golden Bough. In the Fisher King stories, a journeyer comes to a barren land and discovers a wounded king whose wound has caused the land to become sterile. In some cases, the wounding of the king was sexual in nature. Because these ancient peoples believed that the king and the land were united as one and that they reflected on each other, it was necessary to heal the king in order to heal the land. The journeyer then needs to undertake a quest (which fits the archetypal hero's journey pattern) to heal the wounded king and, through him, the land. In the Grail legends, which are frequently intertwined with the Fisher King legends, a questor searches throughout the land for the Holy Grail, undergoing tests of purity, his character, and his dedication to the quest on the way. The nature of the Grail differs from one account to another: It is sometimes thought of as a cup which caught the blood of Christ when he was pierced by a spear while hanging on the cross (which may be derived from the Celtic l egends describing the Grail as a cauldron of rebirth which allowed resurrection to warriors killed in battle but did not allow them to speak of the experience of rebirth -- a pattern into which the story of Lazarus roughly falls), and it is sometimes thought to be a stone (in Eschenbach's Parsifal, the Grail is described as a gem struck from the crown of Lucifer when he was ejected from Heaven).

Belief Systems and Gender Roles in Dracula :: Dracula Essays

Belief Systems and Gender Roles in Dracula There is a classic "good versus evil" plot to this novel. The evil of course being Count Dracula and the Good being represented by the Harkers, Dr. Seward and Lucy, Arthur, Quincy and the Professor. It is the continuing battle between Dracula and the forces of good. Good in this case is the Christian God. The battle is foretold by the landlady where she says, "It is the eve of St Georges Day. Do you no know that tonight, when the clock strikes midnight, all the evil things in the world will have full sway?" and she hands Harker a crucifix (p 12). The crucifix and the empty cross are symbols of fear, loathing and danger to Dracula. There is a certain irony here as the cross is the ultimate symbol of redemption to all Christians. Sin or rather the dark side of humanity's turning from God is recognized and can be redeemed by coming to the cross. The cross is also a symbol of resurrection. The resurrection is the gift of eternal life through Christ to which all Christians can aspire. This is opposed to the Un-Dead nature of Dracula. He is immortal but it is not an eternal joyful thing. Indeed the eternity is always under threat by the very normalcy and goodness of people like the Harkers. This book is set in an age where science and the world of the Enlightenment, that is the world of rational thought and proven theories, ruled. Dr. Seward represents this world. It is opposed to the seemingly unexplainable world of Dracula and his world of mystery and fable. The events that the different characters experience, although documented faithfully are thought too unbelievable by Professor Van Helsing to be passed on (p 486). It is as if the truth can't be handled by the world at large or that by retaining the story to themselves the central characters will preserve a very terrible but precious memory. A memory made precious because of the depths of courage and faith that had to be mined by and in each of them. This is not a case of post-modern thought challenging the modernist attitudes of that Enlightenment nor can it be because post-modernist thought was not formulated in the book's context.

Thursday, July 18, 2019

The Bobo Experiment

The Bobo Experiment was performed in 1961 by Albert Bandura to try and prove that people, especially children, learn their social skills and behaviors from copying or mimicking adults in their lives rather than through heredity genes. Bandura wanted to show, by using aggressive and non-aggressive adult-actors, that a child would be apt to replicate and learn from the behavior of a trusted adult (Shuttleworth, M. 2008). These issues have been present for many years, even before the media used these factors as selling points for newspapers. During the 1960’s, there was several concerns and debates about how children developed whether it be from genetics, environmental factors, or social interactions. For this reason, Bandura created the Bobo Doll Experiment to prove that children are taught from the adults in their lives through role-modeling (Shuttleworth, M. 2008). Bandura had several hypotheses about the results of the Bobo Doll Experiment that were appropriate with his vision on the concepts of social learning (Shuttleworth, M. 2008). 1. Children observing an adult role model operating in an overly hostile manner would be likely to replicate similar behavior themselves, even if the adult was not there (Shuttleworth, M. 2008). 2. Subjects who had witnessed a non-aggressive adult would be less likely to show violent inclinations, even if the adult was not present. They would be even less likely to exhibit this kind of aggression than the control group of children, who had seen no role model at all (Shuttleworth, M. 2008). 3. Bandura believed that children would be much more expected to mimic the behavior of a role model of the same sex. He wanted to show that it was much easier for a child to recognize and relate with an adult of the same gender (Shuttleworth, M. 2008). 4. Bandura’s last prediction was that boys would tend to be more aggressive than girls, because society has always endured and promoted violent behavior in men more than women (Shuttleworth, M. 2008). The results for the Bobo Doll Experiment showed, as expected, that children who were exposed to the aggressive model were more apt to show derivative aggressive behavior themselves. Another prediction was proved correct in that boys were nearly three times more likely to imitate physically violent behavior than girls (Shuttleworth, M. 2008). The overall conclusion of the Bobo Doll Experiment proved to be somewhat incomplete where most of the predictions were not being fully proved. It is not certain that children learn socially, however, it is likely that children watching an adult model using violent behaviors are more apt to believe that this kind of behavior is acceptable. Therefore, they may become users of this type of action themselves when faced with similar situations (Shuttleworth, M. 2008). Bandura discovered that girls were much less likely to become physically violent, but were equally as susceptible to verbal aggression as boys. This finding is often seen in society, where bullying at school, by boys, is more often of a physical nature; intimidation amongst girls tends to be more verbal and social (Shuttleworth, M. 2008). My theory on childhood development is that there are several factors that â€Å"mold† a child into the adult that the child grows to become. These factors include, but not limited to, social interaction with adults and peers, environmental factors, heredity genes (i. e. , bi-polar disorders, ADHD, etc†¦), and the economic standing on their community. Children are susceptible to most things in their lives. One could envision a child as a sponge in that they absorb all information around them. Children learn manners, basic living skills, language, and the like from their closest adults (i. e. , parents, grandparents, teachers, and friends’ parents). Children could possibly inherit disorders that cause obstacles in their learning abilities of how to conduct themselves appropriately in society. I think the most important factor that children learn from the adults and peers in their lives are how to solve problems with a little confrontation as possible. I feel that most adults today have trouble in this particular area; therefore, these adults are inadvertently teaching their children the same problem-solving skills that they hold when in actuality these adults want their children to solve their problems in a different and better way. The factor of an economic standing of their community is that if a child and their family live in a community of poor value, there tends to be less opportunities for a child to develop the necessary skills to survive and be self-sufficient in today’s world. The communities of today need to provide outlets for children to express their dreams, concerns, and goals where the child feels safe. I think every community should have some sort of community center or boys & girls club that promotes activities for the children, counseling for the children who need and want it, study tutors for children who need assistance with their homework, and proper teachings of appropriate social interaction. In my personal life, I have discovered that, as an adult, I replicate today a lot of my mother’s behaviors that I saw when I was a child. Remember saying to yourself, â€Å"I’ll never grow up to be my mother! † I do. Unfortunately, I have become her as an adult through how I conduct my attitudes, moods, facial expressions, and outlook on life. Through what I know of myself and what I experienced as a child, I can say with certainty that children are very influenced by their parents’ behaviors, attitudes, and moods. Children tend to believe that their parents are perfect and can do no wrong. I think that children are too young to realize that their parents are human just like they are and are just as likely to make several, if not numerous, mistakes on a daily basis. Without question, children are influenced, guided, and â€Å"molded† by the factors of life that surround them. References Shuttleworth, M. (2008). The Bobo doll experiment. (pp. 1-1). Experiment-Resources. com. Retrieved July 10, 2009, from Experiment-Resources. com. http://www. experiment-resources. com/bobo-doll-experiment. html#ixzz0KuMD9ZEw&C